Planing soil working devices consisting of a combination of edges and surfaces have to grade and level all types of soils. In the past these devices were constructed with their edges and surfaces fixed rigidly within a vehicle drawn frame work, as is shown in my prior patents. When grading hard soils, it is advantageous to have an edge or scraper to penetrate and cut soils to facilitate moving the soil while trailing planing beams or surfaces flow out the soil and secure a smooth surface. On the other hand in loose or soft soils (soils that do not easily compact such as sand or peat) it is helpful to have all surfaces on the planing device to act as flotation members or skids to prevent gouging and to hold up the weight of the tool while moving the soil. Thus, there has been a long and unfilled need in the field for an adjustable attachment on the scraper or edge of a planing device to allow the scraper to be changed from an edge to a flat surface and vice versa as desirable.
An adjustable edge to flat surface arrangement also aids when soil moisture changes when an edge is usually needed in dry, hard ground and a surface is needed in wet, soft soils.
New tractor operators grading with planing devices also prefer surfaces to compensate for their lack of experience while well-trained tractor operators prefer an edge equipped planing device for more, efficient tractor - planer operation. This is particularly the case with a planing device mounted on a skid-steer loader tractor.
There is definitely a need for a more versatile improved grading device.